a(n) = binomial(n+2,n)^6.

Terms

a(0) =1a(1) =729a(2) =46656a(3) =1000000a(4) =11390625a(5) =85766121a(6) =481890304a(7) =2176782336a(8) =8303765625a(9) =27680640625a(10) =82653950016a(11) =225199600704a(12) =567869252041